There is no doubt that PCF 94 didn't suffer any damage in the mine incident. Unless the windows were blown out in the rice incident, I don't think there was any damage. If there was, you can be sure it would have been included in the bronze star citiation.
There is no doubt that a close miss with their mines would not bend heavy brass props. Their mines were not exactly hi powered. Sometimes you could bend/nick the props by running aground, but in the Cau Mau most river bottoms were very soft and silty.
One other point to think about. Rassmann says he was diving for the bottom to keep from getting run over. Truth be told if I ever went over, I would have wanted the boats behind to see me. I might swim perpendicular to the river, to get out of the way, but I want them to see me.
Besides his cookie would have gotten wet.